And I'm still waiting to find out how we're defining "average" for this conversation.
They aren't perfect, and I would submit that they aren't particularly good, overall. To the extent that they are useful, it's only in conjunction with the raw numbers. Anyone who says that a player is good or bad, based solely on the raw numbers is stupid. And anyone who says that a player is good or bad, based solely on the "advanced" metrics is stupid. You have to look at them together.
Okay first of all, you're welcome to look up how win shares are calculated if you really want to know more about this. The formula doesn't actually include team wins in any way so perhaps the title is misleading. It's calculated so that 1 win share is expected to produce 1 win. Which means if you add up the win shares of all the players on a team for a particular season you should expect the total to be equal to the amount of games that team won that season. It's predictive much like Pythagorean Wins in baseball sabermetrics. For OKC this year, the team's total win shares equal 59.4 and they won 59 games so the formula worked very well. We totaled 34.9 win shares and won 28 games so we under-performed the expectation. It's difficult for our team this year though because we had so much roster turnover throughout the course of the season (we had 13 players total 500 or less minutes for us) so there's a lot of small sample size issues skewing the results. The season before we had a much more stable roster and totaled 28.1 win shares and won 28 games.
So that's what win shares are all about. It stands to reason though that players getting more minutes are going to accumulate more win shares over the course of a season. So we need a way to even the playing field a bit and that's where WS/48 comes in. For Rudy Gay this season he totaled 4.8 combined offensive and defensive win shares. Divide that by 2531 minutes played and you get .0018965 WS/min and multiply by 48min to get .091 WS/48.
Your question was about what .100 means though. Here's where it comes from --
An NBA game has 240 minutes available (48min x 5 positions on the floor).
Let's assume an average team has a regular rotation of about 8 players getting most of the minutes.
Dividing the available minutes equally (240/8) means each player averages 30 minutes per game.
30 minutes per game x 82 games = 2460 minutes played per season so...
Each of our 8 average players is going to play 2460 minutes.
An average team wins 41 out of 82 games so...
Each of our 8 average players is going to accumulate (41/8) = 5.125 Win Shares per season.
(5.125 Win Shares / 2460 minutes played) x 48 min = .100 WS/48
Now you could change the distribution of minutes around and it's not going to change the result, just make the math more complicated. The .100 baseline is calculated so that a team composed entirely of average players is mathematically right in the middle -- they win 50% of their games. It's a baseline expectation by which to evaluate performance. If a player is on the floor for 2460 minutes in a season and produces less than 5.125 win shares than they are falling short of the 41 game win standard and thus are considered below average.
Whether this is actually below league average is going to vary from season to season, but I think we all agree that the goal here is not to win 41 games per season but to win substantially more than that. And with that goal in mind, WS/48 is a predictive tool for estimating how likely it is that a team is going to win. You could set the standard wherever you want actually. Let's say you want the 4th seed in the Western Conf. The average win total to get the 4th seed for the last 5 seasons (I excluded the lockout shortened year) is 54.4 wins so you should shoot for 55 wins to secure that spot. (55 wins/8) = 6.875 WS /2460 min x 48 = .134 WS/48. You want 8 players whose combined WS/48 average is .134 to secure home court in the first round of the playoffs.
It's not an exact science of course, it's merely a predictive model and a different way to think about building a team. All sorts of other factors like coaching and team chemistry are going to affect your results as well. Maybe as an experiment we could project WS/48 numbers for the opening day roster this season and use that to predict how many games we'll win. The projected WS/48's are going to be tricky though. For the young players it would be inaccurate to just go with career averages.
Not really seeing how those previous seasons are relevant to this discussion. You're going to have to present a way stronger argument to convince me how Gay's numbers relative to Prime!Artest, Prime!Granger, Prime!Turkoglu or Prime!Wallace have any bearing on whether or not we need him in 2014-15. Unless you're trying to make the case that we'd be better off with Wallace right now, based on the numbers he put up 2007-11? Granger was a better player than Gay, but that guy ain't coming back through the door. Artest from 2007 would be a way better fit than Gay; do you think that Artest from 2014 is? Also, given my rather vocal anti-tank position, I think that it should go without saying that I'm not as sold on the prospects as you are; I'm absolutely not prepared to say with confidence that any of those kids are going to be as good as Gay in the next three years, let alone next year. And they're not in play for us, anyway, so they're not particularly pertinent to our decision.
Previous seasons are relevant because we were discussing where Rudy Gay ranks compared to other SFs in the league. For his career he's put up a lot of big numbers without ever coming close to being a top 10 SF in the league. I realize that vintage Wallace, Artest, Peja, Granger et al are no longer better options for us at SF put the bigger point I was making is that one season alone is hardly enough of a sample to declare anybody a top 5 player at his position. We always consider multiple seasons when we're making these kinds of assertions don't we? And if you're going to pay Rudy Gay a near-max salary for 4 more years based on the idea that he's a top 5 player at his position, I think it is relevant who is coming into the league who might challenge that assertion over the length of the contract. Even before we talk about 2 of the top 3 prospects in this year's draft playing SF there's also a crop of young forwards who are just starting their NBA careers and could get substantially better over the next 4 years. Evan Turner, Kawhi Leonard, Harrison Barnes, Tobias Harris, Moe Harkless, Derrick Williams, Otto Porter, Anthony Bennett, Michael Kidd-Gilchrist. Any one of them could move into the upper tier over the next 4 years. By some numbers, Leonard is already there. Harris and Kidd-Gilchrist are trending upward.
And, when you look at them together, as they pertain to Rudy Gay, they say that he's probably better than you think he is. Not elite, not worth $19M, but probably better than you think he is. He's slightly above average; a gentleman's B-minus, if you will. And to me, the question isn't so much "Who betta than Gay?" as it is, "Who betta than Gay, whom we could reasonably sign?
So after all of that, we're really just arguing the same point aren't we? Rudy Gay is slightly above average. That's what I've been saying. WS/48 thinks he's slightly below the 41 game standard but PER says he's just a little better than the average starter. And considering the average starter probably doesn't quite meet the 41 game standard either, these stats are actually in pretty close agreement with one another. When you understand that a 41 win team is considered baseline average, it makes sense why our ideas of what constitutes an "average player" might be radically skewed at this point. We haven't won 41 games here in almost a decade. And that's why I don't think it's fair to compare Rudy Gay to the history of the SF position on the Sacramento Kings. Not unless your goal is sustained mediocrity.
I don't have an easy answer to your question but it's clear to me where our two points of view come from. You think a slightly above average Rudy Gay even overpriced is better than nothing. I'd rather a black hole at the position than a 4 year contract which commits us to losing money (relative to production) for the next 4 years. Even if we're in a small market I can't in good conscience sign off on a deal which is mathematically not in our favor. The numbers say Rudy Gay's production is replaceable for half the cost. Of course, numbers aren't everything. No amount of money is going to replace that smile.